Marinade: Combine the orange and lime juices, the vinegar, piloncillo, garlic and bay leaves in a liquid measuring cup. Stir to dissolve the piloncillo.

For the pork: If using the banana leaves, lay one of them in the long side of a deep baking dish large enough to hold all of the pork. Layer the remaining banana leaves so that all sides of the baking dish have an overhang of banana leaves, which will be used to fold over the meat.

Preheat the oven to 350 degrees. Season the tenderloins all over with the salt and pepper.

Heat the oil in a large skillet over medium-high heat. Once the oil shimmers, add half of the pork and sear for about 2 minutes on each side. Transfer to the lined baking dish. Add the remaining pork to the skillet and repeat the cooking process.

Once all of the pork is arranged in the dish, pour the marinade over the meat. Use tongs to turn the meat over so it is evenly coated. Fold the banana leaves over the meat to cover it completely. If you're not using banana leaves, seal the baking dish tightly with aluminum foil. Bake for 1 hour and 20 minutes; uncover carefully (to avoid the steam). The meat should be tender, with an internal temperature of no more than 145 degrees. Use tongs to transfer the meat to a cutting board to rest while you reduce the marinade; cover loosely to keep warm (use a banana leaf or foil).

Discard the bay leaves. Pour the marinade into a medium saucepan and place over medium-high heat. Cook for 10 to 15 minutes or until reduced by half.

Cut the meat crosswise into ½-inch slices. Serve with some sauce drizzled over the top, and pass the remaining sauce at the table.

This recipe is adapted from "Pati's Mexican Table: The Secrets of Real Mexican Home Cooking," by Pati Jinich (Houghton Mifflin Harcourt; $30).